Lots o' Problems...

VestaviaPirate · May 18, 2011

98 XJ Sport, 197k miles.

Changed to the 5.0 injectors last summer. In the spring changed the plugs and wires. I've cleaned the cap and the button.

I started to see a pretty bad misfire. OBD says it is a 301 code (cyl. 1 misfire) I've cleaned the injectors, replaced their o-rings and checked all the plugs and wires. I did a compression test and typically see low compression in 1, with the others very close to each other. The other day I did another test and they were: 1-125, 2-150, 3-129, 4-155, 5-145, 6-155...

I don't know what is going on, there are no other noises I can speak of. You can tell the misfire is there, and the CEL comes on and off occasionally at weird times. I'll be driving around town and the CEL will come on, then a few days later I'll travel home to NC from school in AL and the CEL won't be on at all. It comes and go seemingly for no reason. I've read a bunch of posts, and everything says different things as it applies to me. I don't hear a "tick", don't hear a "hiss". I don't hear anything but the misfire. The fuel pressure seems good, I still need to check that.

This Jeep has a ton of problems it seems, but none of them seem to relate to the engine. I could be wrong. Just to explain: my gas gauge is wrong, it says I have a quarter tank left, but I run out of gas; my blower doesn't work anymore for the A/C or Heat (this just happened); the radio (not OME) will turn off randomly then flash, seems to not get enough power to turn on all the way (this is also very random and occasional).

If anyone can give me any advice, I'm sure I'm missing something and ya'll know the 4.0 a lot more than I will, so let the flaming and hopefully advice commence!

ParadiseXJ · May 18, 2011

VestaviaPirate said:
98 XJ Sport, 197k miles.

Changed to the 5.0 injectors last summer. In the spring changed the plugs and wires. I've cleaned the cap and the button.

Change it, drop the $$ get a new cap

This Jeep has a ton of problems it seems, but none of them seem to relate to the engine. I could be wrong. Just to explain: my gas gauge is wrong, it says I have a quarter tank left, but I run out of gas; my blower doesn't work anymore for the A/C or Heat (this just happened); the radio (not OME) will turn off randomly then flash, seems to not get enough power to turn on all the way (this is also very random and occasional).
QUOTE]

Check all your grounds, not just visually, take them off, clean and shine 'em, put them back, tight.

Have your battery fully charged and then load tested.

Check function of ALL fuses. Not just visually, remove, test, replace as necessary.

Check ALL vacuum lines, replace as necessary, no redneck duct tape repairs, vac line is cheep.

Oh, and since you mentioned it > :flame: J/K :cheers:

All parts are "prone to deteriorization".

old_man · May 18, 2011

How exactly did you clean the injectors?

bails85 · May 18, 2011

pull off each plug wire individually and looked on the inside for white marks and or burns. check the tops of the plug to see if the lttle button is tight. the plug can actually arc out inside of the wire. this will give you a misfire. it took me 3 weeks to figure out what it was on mine. i would change the cap and rotor. i highly doubt it is the injector. try to figure out what cylinder it is by pulling the wires off individually while the motor is on . if there is no change then you know that is it. then unplug the injector and switch it with another one to see if it is the injector. its a time consuming pain in the ass to do this but it works and will lead you to the problem.

VestaviaPirate · May 18, 2011

ParadiseXJ said:
Change it, drop the $$ get a new cap

Check all your grounds, not just visually, take them off, clean and shine 'em, put them back, tight.

Have your battery fully charged and then load tested.

Check function of ALL fuses. Not just visually, remove, test, replace as necessary.

Check ALL vacuum lines, replace as necessary, no redneck duct tape repairs, vac line is cheep.

Oh, and since you mentioned it > :flame: J/K :cheers:

I took the ground off the side panel from the battery and the engine block to the fire wall and cleaned them up real well. What other grounds are suspect or high priority?

How do I fully charge the battery and the load test it? This battery has been in the XJ for almost 3 years (keep using the wal-mart free replacement).

I will pull all the fuses and check visually and with a multimeter.

I know I need to replace all the vac hoses, I just don't know where they all are. I know where they come from, the little ball looking think in my bumper...

old_man said:
How exactly did you clean the injectors?

I soaked them in fuel injector cleaner (seafoam), used a toothbrush and scrubbed em up real good. I also ran seafoam through the fuel system (gas tank) a few times... no change of course. Should I just go back to the old injectors? I figure that there was no problem with them, and the new ones caused this over time.

bails85 said:
pull off each plug wire individually and looked on the inside for white marks and or burns. check the tops of the plug to see if the lttle button is tight. the plug can actually arc out inside of the wire. this will give you a misfire. it took me 3 weeks to figure out what it was on mine. i would change the cap and rotor. i highly doubt it is the injector. try to figure out what cylinder it is by pulling the wires off individually while the motor is on . if there is no change then you know that is it. then unplug the injector and switch it with another one to see if it is the injector. its a time consuming pain in the ass to do this but it works and will lead you to the problem.

I inspected the wires a few times, but will look specifically for these things you mention. I will change the cap and rotor. Can I really just pull the wires off with the Jeep running? I figure that would cause it to misfire by itself. I'll try that too though.

I've switched the injectors around, put the 1st in the #2 cylinder, and no change of codes, but again, if this is a injector thing wouldn't it take a while to hurt that cylinder as it did the #1?

I don't mind spending the time, but I hate wasting it going after things that won't help. Of course I guess all I have to do is trial-and-error.

My dad said it might be a burned valve, does anyone agree/disagree? I just don't see it since all it does is misfire and sputters some when I step on the gas or go up hills. No noise or anything besides the backfire.

Thanks for all the responses, I hope that by the time I have to go back to grad school in August the Jeep will last me another semester or two till I get that big boy job! Thanks again guys.

Any more advice or recommendations would be amazing.

JJacobs · May 18, 2011

155 psi on one cylinder and 125 on another? That's out of spec, too much variance. Time for a leakdown test.

VestaviaPirate · May 18, 2011

JJacobs said:
155 psi on one cylinder and 125 on another? That's out of spec, too much variance. Time for a leakdown test.

I've got one of those, but what does it test for?

ParadiseXJ · May 18, 2011

VestaviaPirate said:
What other grounds are suspect or high priority?

There should be the main battery ground from the battery to the oil dipstick stud...on both my rigs the ECU also grounds there.

How do I fully charge the battery and the load test it? This battery has been in the XJ for almost 3 years (keep using the wal-mart free replacement).

Put the battery on a charger @2-10 amps for 24 hours...disconnected. Then go to AutoZone or similar and ask them to load test it

I know I need to replace all the vac hoses, I just don't know where they all are. I know where they come from, the little ball looking think in my bumper...

Sorry, the vac lines don't originate from the "little ball" AKA vacuum reservoir. Those are just for your HVAC system. The vacuum for that (and everything else) is provided by the hoses coming off the intake manifold.

Here's a diagram:

Can I really just pull the wires off with the Jeep running? I figure that would cause it to misfire by itself.

I, personally, would not pull wires with the Jeep running. Not only will you get a misfire(s) but you'll find out just how much juice is running thru those lines in a big ol' painful hurry. It's a shocking experience, IMO

Hope that helps!!

VestaviaPirate · May 18, 2011

ParadiseXJ said:
Hope that helps!!

That is AWESOME! Thank you for your info!

Out of curiosity, can I just do a load test from a multi-meter? It has a Load setting on there... didn't know if that was the same thing.

What is the best way to replace vac lines? Stealership? Lowes? Idk.

I was worried about the pulling plug wires while running, thought that would of been pretty counter productive as it WOULD produce misfires.

Thank you again, I'll report back once I check all this stuff.

ParadiseXJ · May 18, 2011

VestaviaPirate said:
Out of curiosity, can I just do a load test from a multi-meter? It has a Load setting on there... didn't know if that was the same thing.

What is the best way to replace vac lines? Stealership? Lowes? Idk.

I'd rather have them do it, somebody that is more electronically inclined may chime in.

There are certain vac lines that are pre-fabbed to fit around things in the engine bay. If you go into a NAPA or similar auto parts place they should either have it on hand or can order it. Be sure to specify the year as yours is different than my 88 and 90. You can also get fittings and elbows etc.

For the rest of the lines just buy bulk vac line in the right sizes. I always clip a little end off whatever line I'm replacing, usually sold by the foot, even if you only need a few inches. Bulk line is cheep. The pre-fabbed "harnesses" will run about $40. You can't get them at Lowe's or Home Depot or even the hardware store.

VestaviaPirate · May 19, 2011

ParadiseXJ said:
I'd rather have them do it, somebody that is more electronically inclined may chime in.

I took off the battery cables, cleaned them up, checked the voltage, and even filed them down so that I can clamp them tighter. Seems to be ok in that department. Battery was reading 12.01 volts...

ParadiseXJ said:
There are certain vac lines that are pre-fabbed to fit around things in the engine bay. If you go into a NAPA or similar auto parts place they should either have it on hand or can order it. Be sure to specify the year as yours is different than my 88 and 90. You can also get fittings and elbows etc.

For the rest of the lines just buy bulk vac line in the right sizes. I always clip a little end off whatever line I'm replacing, usually sold by the foot, even if you only need a few inches. Bulk line is cheep. The pre-fabbed "harnesses" will run about $40. You can't get them at Lowe's or Home Depot or even the hardware store.

Ironically, I already figured this out tonight. Took the blower out and accidentally broke two separate lines, one from the HVAC reservoir (or little ball lookin thing) and another I figure is the cruise control (as it has a line to one of the throttle cables). Bought some lines and connected them using the older hoses connectors with the new flexible lines attached. Snug fit, seems to do the trick. Is this how everyone else does it?

I found that the blower not working was because of a loose connection from the power to the blower. I can see that it is melted on both ends, and used contact cleaner and a toothbrush to clean the connectors. Its not a fix, but at least I know what is wrong with it. Any one have any advice on a fix? Its just loose and I'm not sure how to make it fit on there better.

In other news, the Jeep threw a P201 & P202 code. I'm not sure if it's because I unplugged the #1 injector while the Jeep was running, or not. I don't think so, because then why would it give me the 202 code? Weird.

Thanks ya'll. Keep the advice and ideas coming, I hope to knock out all the bugs by next Monday when I start my internship... 20 miles in the opposite direction of my summer job.

BrokenSockets · May 19, 2011

If you took the 24 hour charge advice on the batt and it is only reading 12.01 volts, I think it is weak. A charged battery should read about 12.6 volts after resting for 2 hours after a full charge cycle.

12.01 resting volts is a charge level of less than 50% on a typical automotive lead acid battery.

On the blower - melted connectors could mean that the blower motor is on the way out and it is drawing excess current. It may of course also just mean that the contact was bad which increased the impedance at the connector.

bails85 · May 19, 2011

im sorry for my post of pulling the wires off with the engine running. i didnt see that you already knew what cylinder was missfiring. i meant pull the wire then start the motor. if it get worse you pulled the wrong wire. if it stay the same then you know it is the wire you pulled. i dont think the vaccum system is all that complicated. when i did mine i just kinda checked around the engins bay for split or torn lines then replaced them if needed . actually i replaced them all but copied how they were and did my best to guess as to where they broken ones went. it worked out for me. maybe i got lucky. but the ones that go to the vaccum bottle just need to be connected to it. i dont think it matters if you have them exactly right i just think the lines need to have vaccum to them. but i could be wrong. your cylinder test are way too inconsistent. a leak down test shows if the cylinder hold pressure or not. i use it as a tool to check for a bad head gasket if the dye test comes back inconclusive. you may need a complete rebuild. as far as the missfire goes take it to a reputable shop and have them diagnose it. sometimes its worth the 50 bucks. take the battery to auto zone and have them test it. a volt meter will only tell you so much. im sure there are other opinions on this but thats what i do and it works for me. i only like to rack my brain for so long then i just take it to a shop.

weebur · May 19, 2011

Fuel Gauge: There's a factory recall regarding fuel gauge inaccuracies. Call your local dealer to confirm. They should fix it for free.

Recall: Recall 97V194000: Defective Fuel Gauge Sender

VestaviaPirate · May 20, 2011

BrokenSockets said:
On the blower - melted connectors could mean that the blower motor is on the way out and it is drawing excess current. It may of course also just mean that the contact was bad which increased the impedance at the connector.

I'm going to squeeze the connectors closer together, they seem to be spade connectors. New development: On the way home from work, only the low setting would work. If I cranked it up higher, the blower wouldn't work anymore. Odd. Any ideas?

bails85 said:
i dont think the vacuum system is all that complicated. when i did mine i just kinda checked around the engins bay for split or torn lines then replaced them if needed . actually i replaced them all but copied how they were and did my best to guess as to where they broken ones went. it worked out for me. maybe i got lucky. but the ones that go to the vaccum bottle just need to be connected to it. i dont think it matters if you have them exactly right i just think the lines need to have vacuum to them. but i could be wrong.

I had to replace some of the vacuum lines last night, I accidentally broke them. Is using the soft rubber hoses from Advanced Auto ok to replace the hard lines that are in the XJ?

bails85 said:
your cylinder test are way too inconsistent. a leak down test shows if the cylinder hold pressure or not. i use it as a tool to check for a bad head gasket if the dye test comes back inconclusive. you may need a complete rebuild.

I'm going to do a leak down test this weekend. If it is a bad gasket wouldn't I know/hear it?

bails85 said:
as far as the misfire goes take it to a reputable shop and have them diagnose it. sometimes its worth the 50 bucks. take the battery to auto zone and have them test it. a volt meter will only tell you so much. I'm sure there are other opinions on this but that's what i do and it works for me. i only like to rack my brain for so long then i just take it to a shop.

I'll look into the battery more. I haven't tested it after running the Jeep, but I'm putting it on a charger now...

weebur said:
Fuel Gauge: There's a factory recall regarding fuel gauge inaccuracies. Call your local dealer to confirm. They should fix it for free.

Recall: Recall 97V194000: Defective Fuel Gauge Sender

I will DEF look into this. The gauge goes down to a 1/4th of a tank, then just get stuck it seems. Very annoying when traveling 300+ miles and you don't know when you need to stop for gas. I've done the trip a bunch so I know now, but I'm kinda scared to travel anywhere new because of this. This is why I carry a spare gas can. Thanks!

Thank you so much for all the advice. All the little things seem to be fixed or fixable... I'm still worried about the misfire. I assume if I let it go long enough it will eventually break something... which I don't want... and be very expensive... which I can't afford. I think if it's still like this this time next weekend, I'm gonna give in and take it to a shop. I just feel bad about it since I have/should have every tool in the book, the actual book, and the experience of my father who has rebuilt all sorts of engines in his life time. But thanks again for all this advice and trouble shooting, keep it coming please!

ParadiseXJ · May 20, 2011

VestaviaPirate said:
I had to replace some of the vacuum lines last night, I accidentally broke them. Is using the soft rubber hoses from Advanced Auto ok to replace the hard lines that are in the XJ?

I will DEF look into this. The gauge goes down to a 1/4th of a tank, then just get stuck it seems. Very annoying when traveling 300+ miles...

Yes you can replace the hard lines with soft rubber. Just get the right size and somewhat rigid rubber, not too soft or the vacuum in the bigger lines can suck up the hose.

...and if you're traveling 300+ miles on a tank you're doing better than most of us. I can barely squeeze about 280 out of a fill up before I start sweating. Just to be safe, fill up at 200 (til you get it fixed of course)

VestaviaPirate · May 20, 2011

ParadiseXJ said:
Yes you can replace the hard lines with soft rubber. Just get the right size and somewhat rigid rubber, not too soft or the vacuum in the bigger lines can suck up the hose.

Should I just go ahead and replace all the vacuum lines? Seems to be a smart idea, and the lines are pretty cheap.

ParadiseXJ said:
...and if you're traveling 300+ miles on a tank you're doing better than most of us. I can barely squeeze about 280 out of a fill up before I start sweating. Just to be safe, fill up at 200 (til you get it fixed of course)

I mean, barley 300... Auburn to Gaffney, SC. I'd love to get more, which is why... sadly, I'm looking at Commanders to replace my XJ. Don't worry, still keeping the XJ, love it too much!

VestaviaPirate · May 20, 2011

weebur said:
Fuel Gauge: There's a factory recall regarding fuel gauge inaccuracies. Call your local dealer to confirm. They should fix it for free.

Recall: Recall 97V194000: Defective Fuel Gauge Sender

Will this still be available? Someone said they might not honor it since it is a 13 year old Jeep... just wondering. Thanks!

bails85 · May 20, 2011

that doesnt matter a recall is a recall. they look up your vin number at the dealer to see if your vehicle has a recall on it and they also check to see if it had been repaired or not. if not then they will fix it for free because there was a recall on it.

I'm going to do a leak down test this weekend. If it is a bad gasket wouldn't I know/hear it?

i dont think your head gasket is bad. i just use a leakdown test to second check for a bad head gasket. a leakdown test will only tell you if you have a leak in the cylinder. it can be head gasket leak, a valve leak, or the rings are bad. but if you arent blowing smoke out of your tailpipe then youre rings might still be good. its just hard to tell exactly what it is without playing mechanic on your xj. the vaccumlines are simple get the soft line i went 3/16 instead of 1/8 inch. i used the hard plastic couplers where i needed to splice. it that easy you dont need the hard plastic lines. just run you new lines and zip tie them cleanly and out of the way. slide the new rubber line over the old hard line if you need to.

weebur · May 20, 2011

VestaviaPirate said:
98 XJ Sport, 197k miles.

Changed to the 5.0 injectors last summer. In the spring changed the plugs and wires. I've cleaned the cap and the button.

I started to see a pretty bad misfire. OBD says it is a 301 code (cyl. 1 misfire) I've cleaned the injectors, replaced their o-rings and checked all the plugs and wires. I did a compression test and typically see low compression in 1, with the others very close to each other. The other day I did another test and they were: 1-125, 2-150, 3-129, 4-155, 5-145, 6-155...

I don't know what is going on, there are no other noises I can speak of. You can tell the misfire is there, and the CEL comes on and off occasionally at weird times. I'll be driving around town and the CEL will come on, then a few days later I'll travel home to NC from school in AL and the CEL won't be on at all. It comes and go seemingly for no reason. I've read a bunch of posts, and everything says different things as it applies to me. I don't hear a "tick", don't hear a "hiss". I don't hear anything but the misfire. The fuel pressure seems good, I still need to check that.

This Jeep has a ton of problems it seems, but none of them seem to relate to the engine. I could be wrong. Just to explain: my gas gauge is wrong, it says I have a quarter tank left, but I run out of gas; my blower doesn't work anymore for the A/C or Heat (this just happened); the radio (not OME) will turn off randomly then flash, seems to not get enough power to turn on all the way (this is also very random and occasional).

If anyone can give me any advice, I'm sure I'm missing something and ya'll know the 4.0 a lot more than I will, so let the flaming and hopefully advice commence!

Hey you're welcome, who needs more stress when driving? If you call or go into your dealer have you VIN with you, also, you can and should go to this website and create an account. Through this website you can order a "Build Sheet", it will show all of the options that came with your rig, including all of the recalls that were performed: https://www.jeep.com/hostb/crossbrand/owners/en/

Lots o' Problems...

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